Elevation of either axoplasmic norepinephrine or sodium level induced release of norepinephrine from cardiac sympathetic nerve terminals

1996 ◽  
Vol 737 (1-2) ◽  
pp. 343-346 ◽  
Author(s):  
Toji Yamazaki ◽  
Tsuyoshi Akiyama ◽  
Hirotoshi Kitagawa ◽  
Yuji Takauchi ◽  
Toru Kawada
1991 ◽  
Vol 261 (3) ◽  
pp. H969-H973 ◽  
Author(s):  
L. S. Sun ◽  
P. C. Ursell ◽  
R. B. Robinson

The onset of sympathetic innervation induces a developmental change in the cardiac alpha 1-adrenergic chronotropic response from an increase to a decrease in rate. The mechanism by which innervation induces this alteration is unknown. Neuropeptide Y (NPY), which is found abundantly in cardiac sympathetic nerve terminals, was considered as a possible mediator for this effect. Chronic conditioning by NPY in noninnervated myocyte cultures stimulated the effect of sympathetic innervation in inducing the alpha 1-inhibitory chronotropic response. Chronic conditioning by the NPY antagonist PYX-2 blocked the effect of innervation. Thus endogenous NPY may modulate alpha 1-adrenergic responsiveness during the ontogeny of cardiac sympathetic innervation.


1997 ◽  
Vol 272 (3) ◽  
pp. H1182-H1187 ◽  
Author(s):  
T. Yamazaki ◽  
T. Akiyama ◽  
H. Kitagawa ◽  
Y. Takauchi ◽  
T. Kawada ◽  
...  

We applied a dialysis technique to the hearts of anesthetized cats and examined whether the concentration of dialysate norepinephrine (NE) reflected NE disposition at the cardiac sympathetic nerve terminals. Dialysis probes were implanted in the left ventricular wall, and dialysate NE concentrations were measured as an index of myocardial interstitial NE levels. Stimulation of stellate ganglia significantly increased dialysate NE responses that were suppressed by local administration of an NE-releasing inhibitor (omega-conotoxin GVIA, 10 microM). Increments in basal dialysate NE levels were correlated with concentrations of a locally administered neuronal uptake blocker (desipramine; 1, 10, and 100 microM). Desipramine (100 microM) augmented stimulation-induced dialysate NE responses. Local administration of a neuronal vesicle uptake blocker (reserpine, 1 and 10 microM) did not alter dialysate NE levels but increased dialysate dihydroxyphenylglycol levels. An NE-releasing amine (tyramine, 100 microg/ml) was locally administered to examine NE storage capacity at the nerve terminal. The tyramine-induced NE-releasing response was completely abolished by pretreatment with reserpine (1 mg/kg i.p.). Thus cardiac dialysis with local administration of a pharmacological tool offers a new, concise approach to assessment of neuronal NE release, uptake, vesicle uptake, and storage capacity by cardiac sympathetic nerve terminals.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Seo ◽  
T Yamada ◽  
T Watanabe ◽  
T Morita ◽  
Y Furukawa ◽  
...  

Abstract Background Cardiac sympathetic nerve dysfunction, which is assessed by I-123 metaiodobenzylguanidine (MIBG) imaging, is associated with the poor outcomes in patients with chronic heart failure (CHF). Serial evaluation of cardiac MIBG imaging was shown to be useful for predicting adverse outcome in CHF. However, there was no information available on long-term serial changes of cardiac sympathetic nerve dysfunction after discharge of acute decompensated heart failure (ADHF) hospitalization. Purpose We aimed to clarify the serial change of cardiac MIBG imaging parameter in long-term after discharge of heart failure hospitalization, especially relating to HFrEF (LVEF<40%), HFmrEF (40%≤LVEF<50%) and HFpEF (LVEF≥50%). Methods We studied 112 patients (HFrEF; n=44, HFmrEF; n=23 and HFpEF; n=45) who were admitted for ADHF, discharged with survival and without heart failure hospitalization during follow-up period. All patients underwent cardiac MIBG imaging at the timing of discharge, in 6–12 months and in 18–24 months after discharge. The cardiac MIBG heart to mediastinum ratio (H/M) was calculated on the early image and the delayed image (late H/M). The cardiac MIBG washout rate (WR) was calculated from the early and delayed planar images after taking radioactive decay of I-123 into consideration. Results In HFrEF patients, late H/M was significantly improved from discharge to 6–12 months data (1.60±0.24 vs 1.75±0.31, p<0.0001). Late H/M of HFmrEF patients was also significantly improved from discharge to 18–24 months data (1.71±0.27 vs 1.84±0.29 p=0.043). On the other hand, late H/M of HFpEF patients was not significantly changed. As for WR, WR in HFrEF and HFmrEF patients was significantly improved from discharge to 18–24 months data, although WR of HFpEF was not significantly changed. Conclusion The improvement in cardiac sympathetic nerve dysfunction was observed in patients with HFrEF and HFmrEF, not in HFpEF, after the discharge of acute heart failure hospitalization. Funding Acknowledgement Type of funding source: None


2001 ◽  
Vol 38 ◽  
pp. S39-S42 ◽  
Author(s):  
Hirotoshi Kitagawa ◽  
Toji Yamazaki ◽  
Tsuyoshi Akiyama ◽  
Hidezo Mori ◽  
Kenji Sunagawa

Circulation ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Chang-seng Liang ◽  
Naomi Kenmotsu Rounds ◽  
Erdan Dong ◽  
Suzanne Y. Stevens ◽  
Junya Shite ◽  
...  

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